scholarly journals Transepithelial potential difference of the intestine and gallbladder of Hoplias malabaricus, a freshwater teleost. effect of urotensins I and II

1996 ◽  
Vol 18 (18) ◽  
pp. 83 ◽  
Author(s):  
Maria Amália Pavanato ◽  
Bernardo Baldisserotto ◽  
Roni João Rakoski ◽  
Olga Martins Mimura
Keyword(s):  
Potential Difference ◽  
Freshwater Teleost ◽  
Hoplias Malabaricus ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference ◽  
Transport Of Ions ◽  
In The Beginning ◽  
Stabilization Period

This study analyzed the effect of the injection of urotensin I (UI) and urotensis II (UII) on the stabilization of the transepithelial potential difference (TPD) of the medium intestine, rectum, and gallbladder of Hoplias malabaricus to investigate if the transport of ions in these organs is affected "in vivo" by these neurohormones. The TPD of the medium intestine, rectum and gallbladder was serosa positive, and remained constant since the first measurement. The injection of both urotensins did not alter the stabilization of the TPD of the medium intestine and rectum when compared with saline-injected group. The injection of UI increased the TPD of the gallbladder in the beginning (0-10 min) of the stabilization period and in the interval of 20-30 min of the stabilization period when fishes were killed 2h and 4h after the injection, respectively, in relation to saline-injected group. The UII injection increased the TPD of the gallbladder only in the beginning (time 0) of the stabilization period in relation to saline when fishes were killed 2h after the injection. No changes in the TPD of the studied organs were detected when fishes were killed 4h after the injection of UII. This study confirms the hypothesis that UI and UII can participate in the regulation of the composition of the bile of fishes, since the injection of both hormones altered the TPD of the gallbladder of H. malabaricus.

Calcium secretion in canine tracheal mucosa

1985 ◽  
Vol 59 (4) ◽  
pp. 1191-1195 ◽  
Author(s):  
F. J. Al-Bazzaz ◽  
T. Jayaram
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Potential Difference ◽  
Secretory Process ◽  
Metabolic Inhibitor ◽  
Tracheal Mucosa ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Calcium (Ca) affects many cellular functions of the respiratory tract mucosa and might alter the viscoelastic properties of mucus. To evaluate Ca homeostasis in a respiratory epithelium we investigated transport of Ca by the canine tracheal mucosa. Mucosal tissues were mounted in Ussing-type chambers and bathed with Krebs-Henseleit solution at 37 degrees C. Unidirectional fluxes of 45Ca were determined in tissues that were matched by conductance and short-circuit current (SCC). Under short-circuit conditions there was a significant net Ca secretion of 1.82 +/- 0.36 neq . cm-2 . h-1 (mean +/- SE). Under open-circuit conditions, where the spontaneous transepithelial potential difference could attract Ca toward the lumen, net Ca secretion increased significantly to 4.40 +/- 1.14 compared with 1.54 +/- 1.17 neq . cm-2 . h-1 when the preparation was short-circuited. Addition of a metabolic inhibitor, 2,4-dinitrophenol (2 mM in the mucosal bath), decreased tissue conductance and SCC and slightly decreased the unidirectional movement of Ca from submucosa to lumen. Submucosal epinephrine (10 microM) significantly enhanced Ca secretion by 2.0 +/- 0.63 neq . cm-2 . h-1. Submucosal ouabain (0.1 mM) failed to inhibit Ca secretion. The data suggest that canine tracheal mucosa secretes Ca; this secretory process is augmented by epinephrine or by the presence of a transepithelial potential difference as found under in vivo conditions.

scholarly journals Parallel effects of VX-770 on transepithelial potential difference in vitro and in vivo

2010 ◽  
Vol 9 ◽  
pp. S20 ◽  
Author(s):  
S.M. Rowe ◽  
J.P. Clancy ◽  
M. Boyle ◽  
F. Van Goor ◽  
C. Ordonez ◽  
...  
Keyword(s):  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

In Vivo Measurements of the Transepithelial Potential Difference in Normal and Homografted Tracheas.

2002 ◽  
Vol 53 (4) ◽  
pp. 343-347
Author(s):  
Shuichiro Hayashi ◽  
Haruna Nakaseko ◽  
Tianqun Yang ◽  
Kazuhiko Takeuchi ◽  
Yuichi Majima
Keyword(s):  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference ◽  
In Vivo Measurements

scholarly journals Effect of histamine on airway transepithelial potential difference in vivo.

Ensho ◽  
1994 ◽  
Vol 14 (5) ◽  
pp. 411-415
Author(s):  
Atsushi Chiyotani ◽  
Jun Tamaoki ◽  
Etsuko Tagaya ◽  
Satomi Takeuchi ◽  
Hisashi Takemura ◽  
...  
Keyword(s):  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

scholarly journals Cholinergic control of rabbit tracheal transepithelial potential difference in vivo

1996 ◽  
Vol 9 (8) ◽  
pp. 1632-1636 ◽  
Author(s):  
J. Tamaoki ◽  
A. Chiyotani ◽  
E. Tagaya ◽  
H. Takemura ◽  
K. Konno
Keyword(s):  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Electrochemical profile of K+ and Na+ in the amphibian early distal tubule

1985 ◽  
Vol 248 (2) ◽  
pp. F266-F271
Author(s):  
J. Teulon ◽  
P. Froissart ◽  
T. Anagnostopoulos
Keyword(s):  
Distal Tubule ◽  
Electrochemical Potential ◽  
Potential Difference ◽  
Raw Data ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference ◽  
Ion Activities

Double-barreled microelectrodes selective to either potassium or sodium were used to determine the transepithelial potential difference (VTE) and the intraluminal activity of potassium (alpha LuK) or sodium (alpha LuNa) in the early distal tubule (EDT) of Triturus waltlii in vivo; luminal activities were compared with the corresponding plasma ion activities, alpha PtK and alpha PtNa. The transepithelial equilibrium potentials for potassium (EK(TE] and sodium (ENa(TE] were computed from the respective transmural chemical distributions: they were used to assess the transepithelial electrochemical potential differences [(V-EK)TE and (V-ENa)TE]. By dividing the raw data into three groups of 30% total tubular length (0-30, 31-60, 61-90%), the following results were obtained. 1) VTE increases from +15 to +20 mV (lumen positive) between the first and second portion of the EDT but remains constant thereafter. 2) The alpha LuK/alpha PtK ratio decreases steadily along the EDT from 1.92 to 1.66 and then to 1.32. 3) The values of alpha LuNa/alpha PtNa in the same three subdivisions are 0.79, 0.44, and 0.45. 4) The (V-EK)TE difference is largely positive along the whole EDT: +32, +33, and +27 mV. 5) The (V-ENa)TE difference declines from +9 mV (first portion) to values statistically not different from zero in the last two thirds of the EDT.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide-mediated regulation of transepithelial sodium and chloride transport in murine nasal epithelium

1999 ◽  
Vol 276 (3) ◽  
pp. L466-L473 ◽  
Author(s):  
Heather L. Elmer ◽  
Kristine G. Brady ◽  
Mitchell L. Drumm ◽  
Thomas J. Kelley
Keyword(s):  
Nitric Oxide ◽  
Chloride Transport ◽  
Chloride Secretion ◽  
Inos Expression ◽  
Potential Difference ◽  
Nasal Epithelium ◽  
Sodium Absorption ◽  
No Production ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Transepithelial ion transport is regulated by a variety of cellular factors. In light of recent evidence that nitric oxide (NO) production is decreased in cystic fibrosis airways, we examined the role of NO in regulating sodium and chloride transport in murine nasal epithelium. Acute intervention with the inducible NO synthase (iNOS)-selective inhibitor S-methylisothiourea resulted in an increase of amiloride-sensitive sodium absorption observed as a hyperpolarization of nasal transepithelial potential difference. Inhibition of iNOS expression with dexamethasone also hyperpolarized transepithelial potential difference, but only a portion of this increase proved to be amiloride sensitive. Chloride secretion was significantly inhibited in C57BL/6J mice by the addition of both S-methylisothiourea and dexamethasone. Mice lacking iNOS expression [NOS2(−/−)] also had a decreased chloride-secretory response compared with control mice. These data suggest that constitutive NO production likely plays some role in the downregulation of sodium absorption and leads to an increase in transepithelial chloride secretion.

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